Researchers at AMBER (Advanced Materials and BioEngineering Research) and the School of Physics in Trinity College Dublin have discovered a method of creating wearable sensors by adding graphene to shop-bought rubber bands; the first time this has ever been achieved worldwide. Working with researchers from the University of Surrey, their findings have been published in ACS Nano, a leading international nanoscience publication.
The team – led by Professor Jonathan Coleman, one of the world’s leading nanoscientists – infused rubber bands with graphene, a nano-material derived from pencil lead that is 10,000 times smaller than the width of a human hair. This process is simple and compatible with normal manufacturing techniques. While rubber does not normally conduct electricity, the addition of graphene made the rubber bands electrically conductive without degrading the mechanical properties of the rubber.
Tests showed that any electrical current flowing through the graphene-infused rubber bands was very strongly affected if the band was stretched. As a result, if the band is attached to clothing, the tiniest movements such as breath and pulse can be sensed.
The discovery opens up a host of possibilities for the development of wearable sensors from rubber, which could be used to monitor blood pressure, joint movement, respiration and blood glucose. Other applications of rubber-graphene sensors could be in the automotive industry (to develop sensitive airbags), in robotics, in medical-device development (to monitor bodily motion), as early-warning-systems for cot death in babies or sleep apnoea in adults. They could also be woven into clothing to monitor athletes’ movement or for patients undergoing physical rehabilitation.
AMBER’s Professor Jonathan Coleman said that sensors were becoming extremely important in medicine, wellness and exercise, medical-device manufacturing, car manufacturing and robotics, among other areas. “Biosensors, which are worn on or implanted into the skin, must be made of durable, flexible and stretchable materials that respond to the motion of the wearer,” he explained. “By implanting graphene into rubber, a flexible natural material, we are able to completely change its properties to make it electrically conductive, to develop a completely new type of sensor.
“Because rubber is available widely and cheaply, this unique discovery will open up major possibilities in sensor manufacturing worldwide,” he added.
Corresponding author, Dr Alan Dalton from the University of Surrey continued, “Until now, no such sensor has been produced that meets needs and that can be easily made. It sounds like a simple concept, but our graphene-infused rubber bands could really help to revolutionise certain aspects of healthcare.”
Professor Mark Ferguson, director general of Science Foundation Ireland and chief scientific adviser to the Government said, “Just over a year since it was established as an SFI Research Centre, AMBER’s researchers are working to address the big issues facing modern society – across healthcare, energy, transport and other areas. It’s this type of research that has led to Ireland’s international position as third for nanoscience and sixth for materials science.”
The paper, Sensitive, High Strain, High-Rate, Bodily Motion Sensors based on Graphene-Rubber Composites, written by AMBER researchers along with collaborators from the University of Surrey, is available here.
AMBER is a Science Foundation Ireland-funded centre that provides a partnership between leading researchers in material science and industry to develop new materials and devices for a range of sectors, particularly the ICT, medical devices and industrial technology sectors. The centre is hosted in Trinity College Dublin, working in collaboration with CRANN (Centre for Research on Adaptive Nanostructures and Nanodevices), the Trinity Centre for Bioengineering and with University College Cork and the Royal College of Surgeons of Ireland.